That ''hinge'' that you are describing is called a ''tabernacle'' on a boat. It needs to be designed to be able to take the sizeable side loads that occur above the deck. Tabernacles are more difficult to engineer than simple hinged mast steps that occur right at the deck and where the deck itself can take the side loads of the mast.
BTW, I am amazed that a PVC sleeve was enough to repair a broken mast. PVC has a small fraction of the strength of aluminum or wood.